Streamflow Regime and Changes in Large Northern Watersheds:

Human Impacts vs. Natural Variations

Daqing Yang, Douglas Kane

Water and Environment Research Center

University of Alaska Fairbanks, AK99775

Baisheng Ye

Cold & Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences,

Lanzhou 730000, P. R. China

Table 1. Basic basin information for selected Siberian rivers

River Lat / Lon Basin Permafrost Annual Annual Annual Runoff Data Station (N / E) Area Coverage Precp Discharge Runoff Ratio Period

(1,000 Km2) (%) (mm) (m3/s) (mm)

Lena 70.70 / 127.65 2,430 78-93 390 16,622 216 0.55 1935-94at Kusur (0.46-0.53)

Yenisei 67.48 / 86.50 2,440 36-55 430 17,847 231 0.54 1936-95at Igarka (0.47-0.54)

Ob 66.57 / 66.53 2,950 4-10 470 12,504 134 0.29 1930-94at Salekhard (0.25-0.33)

A

FEDC

HG

IJ

K

ML

NB

A Reservoir

a) Mean monthly temperatures, 1851-1999

-40

-30

-20

-10

0

10

20

30

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Tem

per

atu

re (

c)

Ob Yenisei Lena

b) Mean monthly Precip, 1900-98

0

10

20

30

40

50

60

70

80

90

1 2 3 4 5 6 7 8 9 10 11 12

Month

Pre

cip

(m

m)

Ob

Yenisei

Lena

0

20,000

40,000

60,000

80,000

100,000

120,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

0

20,0 00

40,0 00

60,0 00

80,0 00

100,0 00

120,0 00

J an Feb Ma r Ap r May J un Ju l A ug S ep Oc t N ov D ec

0

20,00 0

40,00 0

60,00 0

80,00 0

1 00,00 0

1 20,00 0

Ja n Fe b Mar A pr Ma y Ju n Jul Au g Se p Oct No v De c

Mon

thly

dis

char

ge (

m3/

s)

Lena river, 1935-94

Yenisei river, 1936-1995

Ob river, 1930-94

Monthly flow regime and change

Comparisons of long-term daily mean discharge

(m3/s)

0

20,000

40,000

60,000

80,000

100,000

120,000

1 31 61 91 121 151 181 211 241 271 301 331 361

Dai

ly d

isch

arg

e (m

3/s)

1955-66

1967-94

Lena

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

1 31 61 91 121 151 181 211 241 271 301 331 361

Dai

ly d

isch

arg

e (m

3/s)

1955-66

1967-95

Yenisei

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

1 31 61 91 121 151 181 211 241 271 301 331 361

Julian day

Dai

ly d

isch

arg

e (m

3/s) 1954-66

1967-94

Ob

y = 14.56x + 11209

R2 = 0.0253

y = 10.865x + 17520

R2 = 0.0136

y = 19.992x + 15937

R2 = 0.0298

0

5,000

10,000

15,000

20,000

25,000

1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995

Year

Salekhard/Ob Igarka/Yenesei Kusur/Lena

Annual discharge and trend for Ob, Yenisei & Lena rivers, 1930-95

Annual precipitation and trend in large Siberian basins, 1935-98

y = -0.0821x + 374.13R2 = 0.0027

y = -0.0268x + 442.68R2 = 0.0002

y = -0.1806x + 464.21R2 = 0.0238

200

250

300

350

400

450

500

550

1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995Year

year

ly p

reci

pit

atio

n (

mm

)

Lena YeneseiOb Linear (Lena)Linear (Ob) Linear (Yenesei)

Vilui reservoir, operated in 1967,max. capacity 35.9km3, 7% Lena River total runoff

EF

D

A

B

C

H

Aldan tributary Area ----28.6% Runoff ---- 30%

Data ---1942-1990

Upper Lena basin Area ----36.9%Runoff --- 42%

Data ---1936-1990

Vilui basin Area ---18.6%Runoff ---- 9%

Data ---1936-1990

LENA – KUSUR Area ----2,430,000km2

Runoff ---523.9km3 Data ---1939-1994

G

Mon

thly

dis

char

ge (

m3/

s)

0

1000

2000

3000

4000

5000

6000

7000

Jan

Feb Mar

AprM

ay Jun Ju

lAug Sep O

ctNov Dec

010002000

3000400050006000

700080009000

0

2000

4000

6000

8000

10000

12000

14000

16000

Vilui at Chernyshevskyi

0

1000

2000

3000

4000

5000

6000

7000

1936

1941

1946

1951

1956

1961

1966

1971

1976

1981

1986

0

20000

40000

60000

80000

100000

120000

Vilui at Suntar

0100020003000400050006000700080009000

Vilui at Hatyrik-Homo

0

2000

4000

6000

8000

10000

12000

14000

16000

Reservoir Effect on Streamflow

LENA - KUSUR

0

20000

40000

60000

80000

100000

120000

Vilui at Chernyshevskyi

0

500

1,000

1,500

2,000

2,500

3,000

3,500

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

59-67

68-90

Vilui at Suntar

0

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

42-67

68-90

Vilui at Hatyrik-Homo

01,000

2,0003,000

4,0005,000

6,0007,000

8,0009,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

42-67

68-90

LENA - KUSUR

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

43-67

68-90

Monthly mean discharge for pre-dam (1942-67) and post-dam (1968-90) periods at the 4 stations

Mon

thly

dis

char

ge (

m3/

s)

Mean stream temperatures,

predam (1950-67) vs. postdam (1968-

92) periods, Suntar station.

June discharge and June 20

stream temperature,

Suntar station. 0

1000

2000

3000

4000

5000

6000

7000

8000

9000

1950

1953

1956

1959

1962

1965

1968

1971

1974

1977

1980

1983

1986

1989

Year

Dis

char

ge

(m3/s

)

0

2

4

6

8

10

12

14

16

18

Str

eam

Tem

p (

oC

)

discharge stream temp

024

68

101214

161820

May

. 20

May

. 30

Jun.

10

Jun.

20

Jun.

30

Jul.

10

Jul.

20

Jul.

30

Aug

. 10

Aug

. 20

Aug

. 30

Sep

t. 1

0

Sep

t. 2

0

Sep

t. 3

0

Oct

. 10

Oct

. 20

Date

Str

eam

Tem

p (

oC

)

Predam1950-67 Postdam1968-92

Dam Impact on Water Temp:

Monthly discharge trends for major sub-basins and at Lena basin outlet

-3,000

-2,000

-1,000

0

1,000

2,000

3,000

4,000

5,000

6,000

Jan Feb Mar Apr May Jun Jul Aug. Sep Oct Nov Dec

Dis

ch

arg

e t

ren

d (

m3

/s)

Aldan sub-basin /Station BUpper Lena /Station CVilui sub-basin /Staion DLena Basin outlet /Station A

Reconstruction of monthly discharge at basin outlet

Regression functions between upstream and downstream Q:

June: Qoutlet = 0.315+3.315Q1+0.813Q2

May: Qoutlet = 660.8e0.0002Q2

Comparison between the observed and reconstructed monthly discharge at Lena basin outlet / Kusur station

Jan.R=0.69

1,500

2,000

2,500

3,000

3,500

1,500 2,000 2,500 3,000 3,500

MayR=0.79

0

10,000

20,000

30,000

0 10,000 20,000 30,000

1:1

Jun.R=0.67

60,000

70,000

80,000

90,000

100,000

60,000 70,000 80,000 90,000 100,000

1:1

Aug.R=0.91

15,000

20,000

25,000

30,000

35,000

40,000

15,000 20,000 25,000 30,000 35,000 40,000

1:1

Rec

onst

ruct

ed d

isch

arge

(m

3/s)

Observed discharge (m3/s)

1,000

2,000

3,000

4,000

5,000

1935 1945 1955 1965 1975 1985 1995

Jan

Comparison between observed and reconstructed monthly discharge at the Lena basin outlet, 1942-90

30,000

50,000

70,000

90,000

110,000

1935 1945 1955 1965 1975 1985 1995

Observation reconstructed

Jun

Mon

thly

dis

char

ge (

m3/

s)

(a) mean discharge

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

Jan. Feb. Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Mon

thly

mea

n di

scha

rge

(m3/

s)

Observed

Reconstructed

(b) discharge trend

-3,000

-2,000

-1,000

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

Jan. Feb. Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Mon

thly

dis

char

ge t

rend

(m

3/s)

Observed

Reconstructed

Comparison of observed vs. reconstructed mean flows at Kusur station

Comparisons of annual discharge and its trend,

observed vs. reconstructed, Lena basin outlet

12,000

14,000

16,000

18,000

20,000

22,000

24,000

1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000

Year

Ann

ual D

isch

arge

(m

3/s)

Observed Reconstructed

Linear (Observed) Linear (Reconstructed)

A

FED

C

HG

IJ

K

ML

NB

A Reservoir